1. MJO influence on severe weather synoptic conditions
Matthew Vaughan Department of Atmospheric and Environmental Sciences University at Albany/SUNY Albany, NY ATM 401/501 Final Presentation SUNY-Albany Albany, New York Monday 12 May 2014

2. Background
Madden-Julian Oscillation (MJO) is a planetary-scale pattern of winds and convection that propagates eastward
Tropical convection can generate Rossby wave trains that influence mid-latitude flow as they propagate towards the poles (Sardeshmukh and Hoskins 1988)

3. Motivation 1974-2010 (all year)
Thompson and Roundy (2012)
Fraction of days categorized as VTDs by RMM phase >1.0 amplitude (solid bars). Periods when RMM amplitude was <1 appear in the “<1” bar, and the full climatology appears in the “All” bar. Clear bars and lines within the solid bars together represent the 90% confidence interval obtained from a Monte Carlo test.

4. Motivation 1974-2010 (March, April, and May)
Thompson and Roundy (2012)
Fraction of days categorized as VTDs by RMM phase >1.0 amplitude (solid bars). Periods when RMM amplitude was <1 appear in the “<1” bar, and the full climatology appears in the “All” bar. Clear bars and lines within the solid bars together represent the 90% confidence interval obtained from a Monte Carlo test.

5. Motivation
Aid in medium range forecasting skill for convection in the Eastern CONUS
MJO lead times of days demonstrated by Maharaj and Wheeler (2005).

6. Methodology
MJO phase determined by Real- time Multivariate MJO (RMM) index (Wheeler and Hendon 2004)
Dataset consists of phase-2 MJO events between with an RMM amplitude >1
Design algorithm to do this > Algorithm method

7. Methodology
Build composite mean and anomaly charts to assess synoptic conditions surrounding phase- 2 MJO events using NOAA/ESRL software
Examine days leading up to during, and after the onset of phase-2 MJO event.
Design algorithm to do this > Algorithm method

8. Results
16 MJO phase-2 events occurred between during March, April, and May (MAM) with an RMM amplitude >1
11 events met the criteria for inclusion based on ENSO conditions

9. Results
a.)
b.)
c.)
Composite 300-hPa geopotential height anomaly (contour interval of 20 m with warm colors positive and cool colors negative) Time lags of (a) -7, (b) -3, (c) 0, days until the onset of the MJO.

10. Day +1
a.)
b.)
c.)
Composite (a) 500-hPa geopotential height anomaly (interval of 20 m), (b) 850-hPa geopotential height anomaly (interval of 10 m), and (c) columnar precipitable water anomaly (interval of 1 kg/m2)

11. Day +3
a.)
b.)
c.)
Composite (a) 500-hPa geopotential height anomaly (interval of 20 m), (b) 850-hPa geopotential height anomaly (interval of 10 m), and (c) columnar precipitable water anomaly (interval of 1 kg/m2)

12. Day +5
a.)
b.)
c.)
Composite (a) 500-hPa geopotential height anomaly (interval of 20 m), (b) 850-hPa geopotential height anomaly (interval of 10 m), and (c) columnar precipitable water anomaly (interval of 1 kg/m2)

13. Conclusion
MJO is an important teleconnection feature for mid-latitude weather patterns
Results suggest Eastern US has more favorable synoptic precursors to severe weather during MAM phase-2 MJO
MJO-factor can influence medium-range forecasts

14. Day +7
a.)
b.)
Composite (a) 500-hPa geopotential height anomaly (interval of 20 m), (b) 850-hPa geopotential height anomaly (interval of 10 m).